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20120820b

Decimal → binary conversion

Convert a decimal integer to binary format.

Example: 156 in binary format:

        quotient    remainder
156 / 2 = 78           0
78  / 2 = 39           0
39  / 2 = 19           1
19  / 2 = 9            1
9   / 2 = 4            1
4   / 2 = 2            0
2   / 2 = 1            0
1   / 2 = 0            1

That is: divide the decimal number by 2 until the quotient becomes 0. At that point the algorithm stops. Reading the remainders from bottom to top we get the binary number: 10011100.

Exercise: write a program that converts an arbitrary positive integer to binary.

Note: do this conversion manually (like above). However, there is a built-in function called bin() that can do it for you.